Gauss double type object-lens



United States Patent ABSTRACT OF THE DISCLOSURE Gauss double type object-lenses comprising, in order from the front, (1) two simple converging meniscus lenses, the convexity of each being to the front, (2) two diverging meniscus doublet-lenses, the concavities of each facing each other, and (3) a converging system consisting of two identical converging lenses.

The Gauss double type object-lenses comprise, in order from the front, two converging simple meniscus lenses the convexity of which is to the front, two diverging doubletlenses in the form of menisci the concavities of which face each other, and a converging system.

The invention has for object an object-lens of this type permitting a large opening, of the order of F:1.0 and a very satisfactory correction of spherical aberrations, coma, field curvature, astigmatism, distorsion andchromatic aberrations.

The object-lens according to the invention is characterized by the fact that the converging elements'have an Abbe number higher than 45 and the diverging elements an Abbe number lower than 45, and by the following relationship limits for the curvature radii:

Two embodiments of the object-lens forming the object of the invention are described hereafter by way of examples, with reference to the following drawing, in which:

FIG. 1 is a diagrammatic section of the object-lens.

FIGS. 2 and 3 respectively show the spherical aberrations and the sine condition.

This object-lens comprises in order from the front: two converging lenses L and L in the shape of menisci. These lenses are followed by a first doublet-lens formed by a doubleconvex lens L coupled'to a double-concave lens L this whole forming a diverging doublet-lens in the shape of a meniscus. This first doublet-lens is followed by a diverging second doublet-lens formed by a doubleconcave lens L coupled to a double-convex lens L The second doublet-lens is followed by two similar doubleconvex lens L and L identical one to the other. The

. focal plane is designated by F.

The curvature radii of the different lenses are indicated starting from the front of the object-lens to the back by R R R The thicknesses of the lenses and the air gaps between them are indicated by d d d 2 Claims 3,488,108 Patented Jan. 6, 1970 ice The two embodiments are defined by the values indicated in the two following examples:

EXAMPLE I Focal length=1 Relative 0pening=F:1.'0

Curvature radius Axial distance Refractive Abbe Number index (11) Air R1=+L4859 d=0.0044 Air R =+L2175 di=0.1045 1. 6700 47. 19 R4=+3.8055

11 :0.0044 Air R =+0.4783

di=0.2570 1. 7130 53.89 R0=-12J189 dt= 0.0261 1. 0989 30. 05 R =0.2696

d1=0.2788 Air Rg=0.3968

d =0.0261 1.6989 30. 05 R =+L6898 d,=0.2439 1. 7131 53. 89 v R1o=-0.6325

dm=0.0044 All Ru=+1.7l11

diz=0.0044 All. R =+1.7111 dia=0.0784 1. 6910 54. 80 R1 =-1.71ll

d14=0.3726 All The aberrations of the ob ect-lens according to Example I are illustrated in FIG. 2, the curve in dash l1nes representing the sine condition, and the full lme curve the spherical aberration in relation to the relative opening.

' EXAMPLE II Focal length=1 Relative opening=Fz 1.0

Curvature radius Axial distance Refractive Abbe Number index (v) Air R1=+1.5252

d =0.1023 1. 6700 47. 19 R3=+5J743 dz=0.0016 Air R,=+1.2083

. da=0.1067 1. 6700 47. 19 R4=+3.9145

dl=0.0016 Air Rs=+0.4876

d.=0.2572 1. 7170 47. 90 R0=10.376 I du=0.0274 1. 6089 30. 05

d =0.2851 Air R =-0.3800

d.= 0.2594 1. 6204 60. 29 R1o=0.5199

d10=0,0016 All R11=+1.4103

. dn=0.0016 Air R13=+L4108 dia=0.0788 1.6910 7 54. 80 R14==2.293O

d14=0.3838 All The aberrations of the ob ect-lens accordlng to Example II are illustrated in FIG. 3, the curve in dash lines representing the sine condltion, and the full line curve the spherical aberration in relation to the relative opening.

lenses and lower than this value for the diverging lenses. In Example I, all the lenses have an index higher than 1.66, but it is not here question of an indispensable measurement, as shown in Example II, in which the lens L shows a refraction index lower than this value.

The two lenses L and L need not necessarily be similar, and these lenses could moreover be replaced by a single converging element having a pronounced curvature.

I claim: I p

1. A Gauss double type objective lens comprising, in order from the front, (1) two simple converging meniscus lenses, the convexity of each being to the front, (2) two diverging meniscus doublet-lenses, the concavities of each facing each other, and (3) a converging system consisting of two identical converging lenses, said objective lens having the following numerical data:

EXAMPLE I Focal length=1 Relative openlng=F:1.

Curvature radius Axial distance Refractive Abbe Number index (I!) Air R +1.4859

dr=0.0044 Air R +1.2l75

d 0.0044 Air R =+0.4783

d =0.2570 l. 7130 53. 89 R 12.489

da=0.0261 1. 6989 30. 05 R =0.2696

d =0.2788 Air R 0.3968

dn=0.2439 1. 7131 53. 89 R1o='0.6325

d=0.0044 A1! R =+1.7111

* dn= 0.0784 1. 6910 54. 80 RI -1.7111

d =0.0044 Air R +1.7111

du=0.3726 Air wherein R -R inclusive, are the values of the radii of the refracting surfaces, counting from the front to the rear of said objectivelens, said values having the sign when convexity is directed to the front and the sign when convexity is directed to the rear; d d d d d d d and d are the values for the axial thicknesses of the lens elements and d d d d and d are the values for axial distances of the air gaps between the component lenses and d is the value for the axial distance of the air gap between the component lens and the focal plane, counting from the front to the rear of said objective lens, said values for the refractive index and Abbe number being those of the respective lens material of said lenses of said objective lens. I

2. A Gauss double type objective lens comprising, in order from the front, (1) two simple converging meniscus lenses, the convexity of each being to the front, (2) two diverging meniscus doublet-lenses, the concavities of each facing eac hother, and (3) a converging system consisting of two identical converging lenses, said objective lens having the following numerical data:

EXAMPLE II Focal lcngth= 1 Relative opening= F: 1.0

Curvature radius Axial distance Refractive Abbe Number index (11) 7 Air R =+L5252 d1=0.1023 1. 6700 47. 19 Rs=+5.1743

d1=0.0016 Air R;=+l.2083

da=0.1067 1. 67 47. 10 R4=+3.9145.

d|=0.0016 Air R +0.4876 v ds= 0.2572 1. 7170 47. 90 Ro=l0.376

do= 0.0274 1. 6989 30. 05 R +0.2730

- d =0.285l Air R3=0.380O

da= 0.0252 1. 6989 30. 05 R +1.7633

dw=0.0016 All R11= +1.41% 1 dn=0.0788 1. 6910 54. Rn= 2.2030

d =0.0010 Air R13: +1.4108

. d| =0.0788 i. 0110 64. 80 Rr4=2.2930

d 4=0.3838 All wherein R R inclusive, are the values of the radii of the refracting surfaces, counting from the front to the rear of said objective lens, said values having the sign when w convexity is directed to the front and the sign when convexity is directed to the rear; d d d d d d d and d are the values for the axial thickness of the lens elements and d d d d and d are the values for axial distances of the air gaps between the component ReferencesCited UNITED STATES PATENTS 8/1935 Lee 350218 X 2/1955 Angenieux 350-215 JOHN K. CQRBIN, Primary Examiner 

